<p>A triple-valve internal blow out preventer having unitary construction is provided, each valve including a tubular assembly having a central passageway with upper and lower seats mounted therein. A ball is rotatably received between the upper and lower seats and includes an external surface and a central opening, wherein the central opening may include an undercut. A protective coating may also be applied to both the external surface and the undercut of the ball to increase the durability of each of the valves.</p>
申请公布号
WO2007021422(A3)
申请公布日期
2008.02.21
申请号
WO2006US27752
申请日期
2006.07.17
申请人
VARCO I/P, INC.;SENEVIRATNE, PADMISIRI, DAYA;WELLS, LAWRENCE;MASON, DAVID, B.
发明人
SENEVIRATNE, PADMISIRI, DAYA;WELLS, LAWRENCE;MASON, DAVID, B.